Defining core patient descriptors for perforated peptic ulcer research: international Delphi

BACKGROUND

Perforated peptic ulcer (PPU) remains a common condition globally with significant morbidity and mortality. Previous work has demonstrated variation in reporting of patient characteristics in PPU studies, making comparison of studies and outcomes difficult. The aim of this study was to standardize the reporting of patient characteristics, by creating a core descriptor set (CDS) of important descriptors that should be consistently reported in PPU research.

METHODS

Candidate descriptors were identified through systematic review and stakeholder proposals. An international Delphi exercise involving three survey rounds was undertaken to obtain consensus on key patient characteristics for future research. Participants rated items on a scale of 1-9 with respect to their importance. Items meeting a predetermined threshold (rated 7-9 by over 70 per cent of stakeholders) were included in the final set and ratified at a consensus meeting. Feedback was provided between rounds to allow refinement of ratings.

RESULTS

Some 116 clinicians were recruited from 29 countries. A total of 63 descriptors were longlisted from the literature, and 27 were proposed by stakeholders. After three survey rounds and a consensus meeting, 27 descriptors were included in the CDS. These covered demographic variables and co-morbidities, risk factors for PPU, presentation and pathway factors, need for organ support, biochemical parameters, prognostic tools, perforation details, and surgical history.

CONCLUSION

This study defines the core descriptive items for PPU research, which will allow more robust synthesis of studies.

Non-contact measurement of the thickness of a surface film using a superimposed ultrasonic standing wave

Most methods used to measure the thickness of thin liquid or solid surface films and coatings need access to the coated surface. In this work reflected ultrasonic pulses were used to measure a coating thickness from a solid back face. Piezoelectric transducers on the solid back face emitted ultrasound waves and received the waves that bounced off the front face. The magnitude of the reflected wave was dependent on the film thickness at the front face. Most pulse-echo ultrasonic approaches use the time-of-flight through the surface layer to determine its thickness. However, as the film becomes thinner, the reflected echoes overlap and there is often an acoustic mismatch between the solid and the surface film that reduces the signal strength. In this work, we propose the use of an ultrasonic continuously repeated chirp longitudinal wave to amplify the effect of the surface film. Multiple reflections interfere within the solid to form a superimposed standing wave whose amplitude spectrum is highly dependent on the surface film thickness thus overcoming the acoustic mismatch problem. Two bare 10 MHz piezoelectric elements were bonded to a 10 mm thick aluminium solid in a pitch-catch arrangement such that one continuously sends repeating chirp ultrasound waves and the other acts as the receiver. The transmitter was set to send a repeating chirp wave of 4 ms duration corresponding to the bandwidth of the transducer in order to maximise signal amplitude. The incident and reflected waves constructively and destructively interfere to form a superimposed standing wave within the solid. The solid/surface film to solid/air boundary condition frequency spectra ratio showed the film resonant frequency modes as minima. Using this technique epoxy coatings ranging from 70 μm to 350 μm were measured and showed a good correlation with independent measurements using a surface profilometer.

A comparison of the psychological outcomes of self-reported and agency-notified child abuse in a population-based birth cohort at 30-year-follow-up

BACKGROUND

Retrospective studies show a strong association between child abuse and subsequent psychiatric morbidity. Prospective studies are less common with conflicting data in young adults. We assessed the effect on psychological outcomes at 30-year follow-up of prospective agency notifications compared to retrospective self-reports of childhood maltreatment in the same birth cohort.

METHODS

We used data on self-reported child abuse from 2425 young adults who completed the Child Trauma Questionnaire (CTQ) at the 30-year follow-up of a prospective birth cohort study commenced in 1981. These were linked to notifications of maltreatment to child protection agencies. The outcomes were DSM-IV diagnoses from the Composite International Diagnostic Interview-Auto version (CIDI).

RESULTS

A quarter of the sample (n=600) self-reported maltreatment of any type, 326 (13.4%) rating this as severe. The most common maltreatment type was neglect (n=382), followed by emotional (n=225), sexual (n=198) and physical abuse (n=197). On adjusted analyses, there were differences between agency- and self-reported maltreatment in the psychological effects on 30-year-olds. In the case of depression, and especially post-traumatic disorder, there were significant associations irrespective of reporting sources. In the case of anxiety, there was a strong association with all forms of self-reported maltreatment. However, agency-reported cases were only significantly associated with emotional abuse in the previous 30-days.

LIMITATIONS

The attrition rate from baseline to follow-up and the possibility of insufficient power to detect statistical significance in agency-reported cases CONCLUSIONS: The association between child maltreatment and psychiatric symptoms may vary by diagnosis and reporting source. Each source possibly captures different populations.

Long-term Cognitive, Psychological, and Health Outcomes Associated With Child Abuse and Neglect

Potential long-lasting adverse effects of child maltreatment have been widely reported, although little is known about the distinctive long-term impact of differing types of maltreatment. Our objective for this special article is to integrate findings from the Mater-University of Queensland Study of Pregnancy, a longitudinal prenatal cohort study spanning 2 decades. We compare and contrast the associations of specific types of maltreatment with long-term cognitive, psychological, addiction, sexual health, and physical health outcomes assessed in up to 5200 offspring at 14 and/or 21 years of age. Overall, psychological maltreatment (emotional abuse and/or neglect) was associated with the greatest number of adverse outcomes in almost all areas of assessment. Sexual abuse was associated with early sexual debut and youth pregnancy, attention problems, posttraumatic stress disorder symptoms, and depression, although associations were not specific for sexual abuse. Physical abuse was associated with externalizing behavior problems, delinquency, and drug abuse. Neglect, but not emotional abuse, was associated with having multiple sexual partners, cannabis abuse and/or dependence, and experiencing visual hallucinations. Emotional abuse, but not neglect, revealed increased odds for psychosis, injecting-drug use, experiencing harassment later in life, pregnancy miscarriage, and reporting asthma symptoms. Significant cognitive delays and educational failure were seen for both abuse and neglect during adolescence and adulthood. In conclusion, child maltreatment, particularly emotional abuse and neglect, is associated with a wide range of long-term adverse health and developmental outcomes. A renewed focus on prevention and early intervention strategies, especially related to psychological maltreatment, will be required to address these challenges in the future.

Self-reported motivations for engaging or declining to engage in cyber-dependent offending and the role of autistic traits

Cyber-dependent offending, i.e. criminal behaviour reliant on computing and the online domain, has been reportedly associated with particular characteristics and motivations such as being young, male, autistic and motivated by challenge. These associations are anecdotal however and empirical evidence is limited. The present study investigated reasons for engaging or declining to commit cyber-dependent offending in cyber-skilled non-offenders (n = 175) and offenders (n = 7) via an online survey measuring cyber-dependent criminality. The potential role of autism and autistic traits was also considered. Qualitative interviews about motivations for offending were carried out with the offenders. The cyber-dependent offenders reported seven main reasons for engaging in cyber-dependent offending: (1) lack of understanding; (2) entertainment; (3) peer influence; (4) experience and career; (5) anonymity and risk perception; (6) life events; and (7) morals. Twenty-nine (approximately 17 %) of the non-offenders had been asked to engage in cyber-dependent offending but had declined. Their reasons and motivations for declining to commit cyber-dependent offences were compared with the cyber-dependent offenders reasons and motivations for engaging in cybercrime. Seven main reasons for declining to offend were identified: (1) moral principles; (2) perception of risk; (3) fear of consequences; (4) not wanting to; (5) wanting to adhere to the law; (6) behaviour being too complicated; and (7) price being too low. Implications for practise are discussed.

Child Maltreatment and Persistent Smoking From Adolescence Into Adulthood: A Birth Cohort Study

OBJECTIVE

A prospective record-linkage analysis to examine whether notified and/or substantiated child maltreatment is associated with the prevalence and persistence of smoking in early adulthood.

METHODS

The sample consisted of 3758 participants enrolled in a population-based birth cohort study in Brisbane, Australia, who were followed up at both 14 and 21 years of age. Suspected experience of child maltreatment was measured by linkage with state child protection agency data. The two main outcomes were the prevalence and persistence of smoking at 21-year follow-up, as well as the 12-month prevalence of nicotine use disorder for participants who completed the Composite International Diagnostic Interview-Auto version.

RESULTS

Of the 3758 young people at the 21-year follow-up, 7.5% (n = 282) had a history of notified maltreatment by the age of 16 years. Of these, 167 cases were substantiated. There were 1362 (35.3%) smokers at 21-year follow-up, although only 220 (5.9%) smoked more than 20 cigarettes daily. Of the 602 participants who smoked at 14 years, 289 were still smoking 7 years later. On adjusted analyses, participants who had experienced any form of notified and/or substantiated maltreatment were approximately twice as likely to be smokers at 21 years old and persistent smokers from 14 years of age. Any form of maltreatment, except sexual abuse, was also associated with an increase in the 12-month prevalence of nicotine use disorders.

CONCLUSIONS

Child maltreatment is associated with both an increased onset and persistence of smoking from adolescence into young adulthood. This may have implications for smoking cessation programs and early interventions for individuals who have experienced maltreatment.

Does child maltreatment predict alcohol use disorders in young adulthood? A cohort study of linked notifications and survey data

BACKGROUND AND AIMS

Most studies of the association between child maltreatment and subsequent problem alcohol use are retrospective. We studied the association of prospectively substantiated child maltreatment with problem alcohol use in adulthood.

DESIGN

We used a prospective cohort record linkage correlational design using data from a statutory child protection agency of prospectively substantiated child maltreatment linked to a birth cohort from a major metropolitan maternity hospital.

SETTING

The Mater-University of Queensland Study of Pregnancy in Brisbane, Australia.

PARTICIPANTS

Of the 3762 young people at the 21-year follow-up, 169 (4.5%) had a history of substantiated maltreatment by 16 years. This was most commonly emotional abuse (n = 90).

MEASUREMENTS

The main outcome was heavy alcohol use at the 21-year follow-up, defined as four or more standard drinks per day. Secondary outcomes were life-time and 12-month diagnoses of alcohol use disorders in  2531 participants who completed the Composite International Diagnostic Interview-auto (CIDI-auto) version. Predictor variables were physical, sexual and emotional abuse, as well as neglect.

FINDINGS

At follow-up, 407 of the 3762 participants reported heavy alcohol use (10.8%). On adjusted analyses, participants who had experienced emotional abuse were significantly more likely to report heavy alcohol use at the time of interview (adjusted odds ratio = 1.856; 95% confidence interval = 1.038-3.319; P = 0.037). Neglect was associated with a life-time CIDI diagnosis of an alcohol use disorder. Other types of child maltreatment were not significantly associated with any of the outcomes.

CONCLUSIONS

Prospectively identified experience of childhood emotional abuse and neglect appears to be positively associated with problem alcohol use at age 21.

Child maltreatment and attentional problems: A longitudinal birth cohort study

OBJECTIVE

To examine whether child maltreatment is associated with attentional problems in adolescence (14 years) and young adulthood (21 years), and whether outcomes depend on the type of maltreatment (sexual vs non-sexual).

METHODS

Data from a population based cohort study involving 3778 mother-child pairs were linked with data from the state child protection agency to examine associations between child abuse and neglect and attention problems, measured using the Achenbach Child Behaviour Checklist (CBCL) and the Achenbach Young Adult Self Report (YASR).

RESULTS

245 (6.5%) participants had been the subject of notification for non-sexual maltreatment (one or more of neglect, emotional or physical abuse) compared with only 54 (1.4%) who had been subject of notification for suspected sexual abuse. After adjusting for potential confounding variables including maternal, participant and sociodemographic factors, we found those exposed to non sexual maltreatment were likely to experience attentional problems at 14 years (p < .001) and 21 years of age (p = .044), compared with those participants who had not experienced non sexual maltreatment. By contrast, at age 14 years, sexual abuse was associated with attentional problems only as reported by the participant, not their carer. Results at 21 years of age for those exposed to sexual child maltreatment (p=.655) were again in contrast to the observed association between attentional problems and non sexual child maltreatment (p = .035).

CONCLUSION

In this study, non-sexual maltreatment in childhood is associated with attentional problems at both 14 years and 21 years of age. These findings highlight the need for targeted research to better understand the longer term mental health outcomes for children exposed to non-sexual maltreatment. Potential implications for mental health services include the need for broader screening at presentation and importantly, greater collaboration with schools, general practitioners and paediatricians, given the greatest impact would arguably be within these settings.

Cognitive and educational outcomes of maltreated and non-maltreated youth: A birth cohort study

OBJECTIVES

Previous research suggests that child maltreatment is associated with adverse outcomes, but the potential impact on cognitive and educational outcomes into adulthood has rarely been studied using a birth cohort design. The aim of this study is to investigate whether child maltreatment is associated with adverse outcomes in cognitive function, high school completion and employment by the age of 21.

METHODS

Longitudinal birth cohort study commencing in the prenatal period, with mothers and infants followed up to age 21. Of the original birth cohort of 7223, 3778 (52.3%) young people participated at age 21. Child maltreatment was identified by linkage with prospectively collected data from the relevant government agency. Associations between child maltreatment (abuse and neglect) and the outcomes were adjusted for relevant sociodemographic and perinatal variables.

RESULTS

After full adjustment, young people who had been notified as cases of child maltreatment had reduced performance on the Peabody Picture Vocabulary Test by over a quarter of a standard deviation (coefficient = -2.85, p = 0.004). Maltreated young people also had three times the odds of failing to complete high school (odds ratio = 3.12, p < 0.001) and more than twice the odds of not being engaged in either study or employment at age 21 (odds ratio = 2.38, p < 0.001). Both abuse and neglect were similarly associated with adverse outcomes.

CONCLUSION

Child maltreatment, including both abuse and neglect, is associated with adverse cognitive, educational and employment outcomes in young adulthood. This adds further impetus to efforts to prevent child maltreatment and assist young people who have experienced it.

Child maltreatment and mental health problems in adulthood: birth cohort study

BACKGROUND

Retrospective studies have shown a high association between child abuse and subsequent psychiatric morbidity. Prospective studies are rarer.AimsTo examine, using a prospective record-linkage analysis, whether substantiated child maltreatment is associated with adverse psychological outcomes in early adulthood.

METHOD

The participants were 3778 mother and child pairs enrolled in a population-based birth cohort study in Brisbane, Australia. Exposure to suspected child maltreatment was measured by linkage with state child protection agency data. The primary outcomes were the internalising and externalising scales of the Youth Self-Report and the Centre for Epidemiological Studies-Depression scales (CES-D) at approximately 21 years of age. A subset completed the Composite International Diagnostic Interview-Auto version (CIDI-Auto).

RESULTS

In total, 171 (4.5%) participants had a history of substantiated child maltreatment, most commonly emotional abuse (n = 91), followed by physical abuse (n = 78), neglect (n = 73) and sexual abuse (n = 54). After adjustment for potential confounders, depressive symptoms on the CES-D, as well as internalising and externalising behaviours were strongly associated with substantiated abuse in all forms, except sexual abuse. The results for the subset of the sample who completed the CIDI-Auto were less clear. Anxiety, especially post-traumatic stress disorder, showed the strongest association whereas the findings for depressive disorder were equivocal. However, across all diagnostic categories, emotional abuse and neglect, as well as multiple forms of abuse, showed a consistent association.

CONCLUSIONS

Child maltreatment, particularly neglect and emotional abuse, has serious adverse effects on early adult mental health. These two warrant the attention given to other forms of child maltreatment. Children experiencing more than one type of maltreatment are at particular risk.Declaration of interestNone.

Characteristics of prisoners with intellectual disabilities

BACKGROUND

Previous studies have found high rates of intellectual disabilities (ID) in prison. However, little is understood about prisoners with ID. This study aimed to identify prisoners with ID and compare their characteristics with prisoners without neurodevelopmental disorders with regard to demographic profile, mental health, suicide risk and offences.

METHOD

This was a descriptive, cross-sectional study carried out using face-to-face interviews with 240 participants in a London Category C prison. Standardised tools were used to assess prisoners for ID and mental disorder.

RESULTS

The study identified 18 prisoners as having ID. Participants with ID were less likely to be from a black or minority ethnic background, be over 35 years of age or have any qualifications. They were more likely to have been single, homeless or unemployed before coming into prison. Prisoners with ID were significantly more likely to have mental health problems and 25% had thought about suicide in the last month and 63% had attempted suicide in the past. Prisoners with ID were also more likely to be housed in the vulnerable prisoners' wing and significantly more likely to have committed robbery than other prisoners.

CONCLUSIONS

The findings confirm the presence of significant numbers of people with ID with high levels of mental illness in a male prison. Services across the CJS are required for this group, specifically, there is a need for raised awareness among those working in prison about ID and improved skills to recognise offenders with ID and address major gaps in current healthcare provision in prison.

Design and operating characteristic of a vacuum furnace for time-of-flight inelastic neutron scattering measurements

We present the design and operating characteristics of a vacuum furnace used for inelastic neutron scattering experiments on a time-of-flight chopper spectrometer. The device is an actively water cooled radiant heating furnace capable of performing experiments up to 1873 K. Inelastic neutron scattering studies performed with this furnace include studies of phonon dynamics and metallic liquids. We describe the design, control, characterization, and limitations of the equipment. Further, we provide comparisons of the neutron performance of our device with commercially available options. Finally we consider upgrade paths to improve performance and reliability.

Child maltreatment and cannabis use in young adulthood: a birth cohort study

AIMS

To investigate whether: (1) child maltreatment is associated with life-time cannabis use, early-onset cannabis use, daily cannabis use and DSM-IV cannabis abuse in young adulthood; and (2) behaviour problems, tobacco use and alcohol use at age 14 are associated with cannabis use.

DESIGN

Birth cohort using linked government agency child protection data to define exposure to child maltreatment.

SETTING

The Mater-University of Queensland Study of Pregnancy in Brisbane, Australia.

PARTICIPANTS

Of the original cohort of 7223 mother and child pairs, obtained from consecutive presentations for prenatal care at a hospital serving a cross-section of the community, 3778 (52.3%) of the young people participated at age 21 years.

MEASUREMENTS

Exposure to child maltreatment was established by substantiated government agency reports. Cannabis outcomes were by self-report questionnaire and Composite International Diagnostic Interview (CIDI)-Auto at age 21. Associations were adjusted for a range of potential confounders. Additional adjustment was carried out for variables measured at age 14-youth behaviour problems [Achenbach Child Behavior Checklist (CBCL)], tobacco use and alcohol use.

FINDINGS

After adjustment, substantiated child maltreatment was associated with any life-time cannabis use [odds ratio (OR) = 1.60, 95% confidence interval (CI) = 1.08-2.39], cannabis use prior to age 17 (OR = 2.47, 95 % CI = 1.67-3.65), daily cannabis use (OR = 2.68, 95% CI = 1.49-4.81) and DSM-IV cannabis abuse/dependence (OR = 1.72, 95% CI = 1.07-2.77). Externalizing behaviour and tobacco and alcohol use at age 14 were associated significantly with almost all cannabis outcomes (P < 0.05), with internalizing behaviour associated inversely (P < 0.05).

CONCLUSIONS

Children in Australia who are documented as having been maltreated are more likely to go on to use cannabis before the age of 17, use cannabis as an adult, use cannabis daily and meet DSM-IV criteria for cannabis dependence. Externalizing behaviour in adolescence appears partly to mediate the association with adult cannabis use.

Rapid, ultra-low coverage copy number profiling of cell-free DNA as a precision oncology screening strategy in metastatic castration-resistant prostate cancer (mCRPC)

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Background: Although cell free DNA (cfDNA) profiling by next generation sequencing (NGS) holds great promise for precision oncology, the inability to estimate tumor content a priori typically results in ultra-deep sequencing (e.g. 10,000x) based approaches—often at limited loci—to ensure accurate assessment of cfDNA samples where tumor content can be < 0.1%. However, a large subset of patients with advanced cancers, where most precision oncology is applied, have much greater cfDNA tumor content. Methods: Here we demonstrate the utility of a pan-cancer, rapid, inexpensive, whole genome NGS of cfDNA approach (PRINCe) on benchtop sequencers as a precision medicine screening strategy based on ultra-low coverage (~0.005x) tumor content determination through genome-wide copy number alteration (CNA) profiling using 48 plasma cfDNA samples from patients with advanced cancer. Results: Using this approach, we identified therapeutically relevant focal CNAs in 13 of 48 (27%) cfDNA samples from patients with metastatic cancer, including 11 of 36 (31%) from patients with mCRPC. We further show that PRINCe is effective at whole genome coverages as low as 0.005x. Combining PRINCe with targeted multiplexed-PCR NGS of the same cfDNA enables mutation and CNA assessment using effective coverage as low as 25x based on calibrating sequencing depth to cfDNA tumor content. Lastly, PRINCe identifies pre-treatment cfDNA copy number profiles that can be used for inexpensive disease monitoring. Conclusions: Taken together, our screening approach enables broadly applicable cfDNA based precision oncology for patients with advanced cancer through rapid, inexpensive identification of therapeutically relevant CNAs and pre-treatment genomic profiles for disease monitoring, while also guiding additional cfDNA profiling approaches to reserve costly ultra-deep approaches for patients with very low cfDNA tumor content.

Characteristics of prisoners with neurodevelopmental disorders and difficulties

BACKGROUND

Previous studies have found high rates of attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID) within the criminal justice system (CJS). However, little is understood about prisoners with neurodevelopmental disorders and difficulties (NDD) or their needs. This study aimed to identify prisoners with NDD and compare their characteristics with prisoners without NDD on a range of socio-demographic and social functioning measures.

METHOD

This was a descriptive, cross-sectional study carried out using face-to-face interviews with 240 participants in a London Category C prison. Standardised tools were used to assess prisoners for ADHD, ASD and ID.

RESULTS

The study identified 87 prisoners who screened positive for one or more type of NDD. Participants with NDD were significantly younger and more likely to be single [(odds ratio) OR = 2.1], homeless (OR = 3.4) or unemployed (OR = 2.6) before they came into prison. They also had poorer educational achievements that those without NDD. Over 80% of those with NDD had a previous conviction or imprisonment.

CONCLUSIONS

The findings confirm the presence of significant numbers of people with NDD in a male prison. Services across the CJS are required for this group; specifically, there is a need for raised awareness among those working in the CJS to improve the recognition of offenders with NDD. Services in the community need to work with individuals with NDD who are at risk of offending, targeting those who are homeless, unemployed and have poor employment opportunities.

Self-reported and agency-notified child sexual abuse in a population-based birth cohort

Child sexual abuse (CSA) has been associated with many adverse psychiatric outcomes. However, most studies have relied on retrospective self-report of exposure to CSA. We set out to investigate the incidence of CSA in the same birth cohort using both retrospective self-report and prospective government agency notification, and examine the psychological outcomes in young adulthood. The primary outcomes were measures of DSM-IV diagnoses (CIDI-Auto) at age 21. The 21-year retrospective CSA questions were completed by 3739 participants. CSA was self-reported by 19.3% of males and 30.6% of females. After adjustment for potential confounders, both self-reported and agency-notified CSA were associated with increased odds of lifetime major depressive disorder (MDD), anxiety disorders, and posttraumatic stress disorder (PTSD). For the first time in a birth cohort, this study has shown the disparity between the incidence of CSA when measured by self-report and government agency notification. Despite this discrepancy, adverse psychiatric outcomes are seen when CSA is defined using either method.

Burden attributable to child maltreatment in Australia

Child maltreatment is a complex phenomenon, with four main types (childhood sexual abuse, physical abuse, emotional abuse, and neglect) highly interrelated. All types of maltreatment have been linked to adverse health consequences and exposure to multiple forms of maltreatment increases risk. In Australia to date, only burden attributable to childhood sexual abuse has been estimated. This study synthesized the national evidence and quantified the burden attributable to the four main types of child maltreatment. Meta-analyses, based on quality-effects models, generated pooled prevalence estimates for each maltreatment type. Exposure to child maltreatment was examined as a risk factor for depressive disorders, anxiety disorders and intentional self-harm using counterfactual estimation and comparative risk assessment methods. Adjustments were made for co-occurrence of multiple forms of child maltreatment. Overall, an estimated 23.5% of self-harm, 20.9% of anxiety disorders and 15.7% of depressive disorders burden in males; and 33.0% of self-harm, 30.6% of anxiety disorders and 22.8% of depressive disorders burden in females was attributable to child maltreatment. Child maltreatment was estimated to cause 1.4% (95% uncertainty interval 0.4-2.3%) of all disability-adjusted life years (DALYs) in males, and 2.4% (0.7-4.1%) of all DALYs in females in Australia in 2010. Child maltreatment contributes to a substantial proportion of burden from depressive and anxiety disorders and intentional self-harm in Australia. This study demonstrates the importance of including all forms of child maltreatment as risk factors in future burden of disease studies.

A new apparatus design for high temperature (up to 950°C) quasi-elastic neutron scattering in a controlled gaseous environment

A design for a sample cell system suitable for high temperature Quasi-Elastic Neutron Scattering (QENS) experiments is presented. The apparatus was developed at the Spallation Neutron Source in Oak Ridge National Lab where it is currently in use. The design provides a special sample cell environment under controlled humid or dry gas flow over a wide range of temperature up to 950 °C. Using such a cell, chemical, dynamical, and physical changes can be studied in situ under various operating conditions. While the cell combined with portable automated gas environment system is especially useful for in situ studies of microscopic dynamics under operational conditions that are similar to those of solid oxide fuel cells, it can additionally be used to study a wide variety of materials, such as high temperature proton conductors. The cell can also be used in many different neutron experiments when a suitable sample holder material is selected. The sample cell system has recently been used to reveal fast dynamic processes in quasi-elastic neutron scattering experiments, which standard probes (such as electrochemical impedance spectroscopy) could not detect. In this work, we outline the design of the sample cell system and present results demonstrating its abilities in high temperature QENS experiments.

Direct load monitoring of rolling bearing contacts using ultrasonic time of flight

The load applied by each rolling element on a bearing raceway controls friction, wear and service life. It is possible to infer bearing load from load cells or strain gauges on the shaft or bearing housing. However, this is not always simply and uniquely related to the real load transmitted by rolling elements directly to the raceway. Firstly, the load sharing between rolling elements in the raceway is statically indeterminate, and secondly, in a machine with non-steady loading, the load path is complex and highly transient being subject to the dynamic behaviour of the transmission system. This study describes a method to measure the load transmitted directly by a rolling element to the raceway by using the time of flight (ToF) of a reflected ultrasonic pulse. A piezoelectric sensor was permanently bonded onto the bore surface of the inner raceway of a cylindrical roller bearing. The ToF of an ultrasonic pulse from the sensor to the roller–raceway contact was measured. This ToF depends on the speed of the wave and the thickness of the raceway. The speed of an ultrasonic wave changes with the state of the stress, known as the acoustoelastic effect. The thickness of the material varies when deflection occurs as the contacting surfaces are subjected to load. In addition, the contact stiffness changes the phase of the reflected signal and in simple peak-to-peak measurement, this appears as a change in the ToF. In this work, the Hilbert transform was used to remove this contact dependent phase shift. Experiments have been performed on both a model line contact and a single row cylindrical roller bearing from the planet gear of a wind turbine epicyclic gearbox. The change in ToF under different bearing loads was recorded and used to determine the deflection of the raceway. This was then related to the bearing load using a simple elastic contact model. Measured load from the ultrasonic reflection was compared with the applied bearing load with good agreement. The technique shows promise as an effective method for load monitoring in real-world bearing applications.

Cryptic and complex chromosomal aberrations in early-onset neuropsychiatric disorders

Structural variation (SV) is a significant component of the genetic etiology of both neurodevelopmental and psychiatric disorders; however, routine guidelines for clinical genetic screening have been established only in the former category. Genome-wide chromosomal microarray (CMA) can detect genomic imbalances such as copy-number variants (CNVs), but balanced chromosomal abnormalities (BCAs) still require karyotyping for clinical detection. Moreover, submicroscopic BCAs and subarray threshold CNVs are intractable, or cryptic, to both CMA and karyotyping. Here, we performed whole-genome sequencing using large-insert jumping libraries to delineate both cytogenetically visible and cryptic SVs in a single test among 30 clinically referred youth representing a range of severe neuropsychiatric conditions. We detected 96 SVs per person on average that passed filtering criteria above our highest-confidence resolution (6,305 bp) and an additional 111 SVs per genome below this resolution. These SVs rearranged 3.8 Mb of genomic sequence and resulted in 42 putative loss-of-function (LoF) or gain-of-function mutations per person. We estimate that 80% of the LoF variants were cryptic to clinical CMA. We found myriad complex and cryptic rearrangements, including a "paired" duplication (360 kb, 169 kb) that flanks a 5.25 Mb inversion that appears in 7 additional cases from clinical CNV data among 47,562 individuals. Following convergent genomic profiling of these independent clinical CNV data, we interpreted three SVs to be of potential clinical significance. These data indicate that sequence-based delineation of the full SV mutational spectrum warrants exploration in youth referred for neuropsychiatric evaluation and clinical diagnostic SV screening more broadly.

Alcohol and tobacco use among maltreated and non-maltreated adolescents in a birth cohort

AIMS

This study examines whether child maltreatment experience predicts adolescent tobacco and alcohol use.

METHODS

The subjects were participants in the Mater-University Study of Pregnancy (MUSP), a birth cohort of 7223, of whom 5158 (71.4%) were available for analysis at the 14-year follow-up. Child protection history was obtained from the state's child protection agency and confidentially linked. Exposure to reported child maltreatment was the primary predictor variable. The outcome variables were self-reported smoking and alcohol use. Associations were adjusted for potential confounders.

RESULTS

Reported child maltreatment was associated with early adolescent smoking [odds ratio (OR) 1.76, 95% confidence interval (CI) = 1.32-2.34] after adjustment for socio-demographic variables and coexisting alcohol use. Both neglect/emotional abuse (OR 2.03, 95% CI = 1.20-3.42) and neglect/emotional abuse that included physical abuse (OR 1.85, 95% CI = 1.19-2.88) were associated with smoking after full adjustment, including for coexisting alcohol use. After full adjustment, including coexisting smoking, only child neglect/emotional abuse predicted early adolescent alcohol use (OR 1.78, 95% CI = 1.06-2.97), but not the other types of maltreatment.

CONCLUSIONS

Reported child maltreatment predicts early adolescent smoking after adjusting for alcohol use, but does not predict alcohol use after adjustment for smoking. Both smoking and alcohol use are predicted by reported child neglect. Early adolescent smoking is also predicted by multi-type maltreatment that includes physical abuse.

Impact of delivery models on understanding genomic risk for type 2 diabetes

BACKGROUND

Genetic information, typically communicated in-person by genetic counselors, can be challenging to comprehend; delivery of this information online--as is becoming more common--has the potential of increasing these challenges.

METHODS

To address the impact of the mode of delivery of genomic risk information, 300 individuals were recruited from the general public and randomized to receive genomic risk information for type 2 diabetes mellitus in-person from a board-certified genetic counselor or online through the testing company's website.

RESULTS

Participants were asked to indicate their genomic risk and overall lifetime risk as reported on their test report as well as to interpret their genomic risk (increased, decreased, or same as population). For each question, 59% of participants correctly indicated their risk. Participants who received their results in-person were more likely than those who reviewed their results on-line to correctly interpret their genomic risk (72 vs. 47%, p = 0.0002) and report their actual genomic risk (69 vs. 49%, p = 0.002).

CONCLUSIONS

The delivery of personal genomic risk through a trained health professional resulted in significantly higher comprehension. Therefore, if the online delivery of genomic test results is to become more widespread, further evaluation of this method of communication may be needed to ensure the effective presentation of results to promote comprehension.

Copy number variation prevalence in known asthma genes and their impact on asthma susceptibility

BACKGROUND

Genetic studies have identified numerous genes reproducibly associated with asthma, yet these studies have focussed almost entirely on single nucleotide polymorphisms (SNPs), and virtually ignored another highly prevalent form of genetic variation: Copy Number Variants (CNVs).

OBJECTIVE

To survey the prevalence of CNVs in genes previously associated with asthma, and to assess whether CNVs represent the functional asthma-susceptibility variants at these loci.

METHODS

We genotyped 383 asthmatic trios participating in the Childhood Asthma Management Program (CAMP) using a competitive genomic hybridization (CGH) array designed to interrogate 20 092 CNVs. To ensure comprehensive assessment of all potential asthma candidate genes, we purposely used liberal asthma gene inclusion criteria, resulting in consideration of 270 candidate genes previously implicated in asthma. We performed statistical testing using FBAT-CNV.

RESULTS

Copy number variation in asthma candidate genes was prevalent, with 21% of tested genes residing near or within one of 69 CNVs. In six instances, the complete candidate gene sequence resides within the CNV boundaries. On average, asthmatic probands carried six asthma-candidate CNVs (range 1-29). However, the vast majority of identified CNVs were of rare frequency (< 5%) and were not statistically associated with asthma. Modest evidence for association with asthma was observed for 2 CNVs near NOS1 and SERPINA3. Linkage disequilibrium analysis suggests that CNV effects are unlikely to explain previously detected SNP associations with asthma.

CONCLUSIONS AND CLINICAL RELEVANCE

Although a substantial proportion of asthma-susceptibility genes harbour polymorphic CNVs, the majority of these variants do not confer increased asthma risk. The lack of linkage disequilibrium (LD) between CNVs and asthma-associated SNPs suggests that these CNVs are unlikely to represent the functional variant responsible for most known asthma associations.

Child maltreatment and adolescent mental health problems in a large birth cohort

OBJECTIVE

To examine whether notified child maltreatment is associated with adverse psychological outcomes in adolescence, and whether differing patterns of psychological outcome are seen depending on the type of maltreatment.

METHODS

The participants were 7,223 mother and child pairs enrolled in a population-based birth cohort study in Brisbane, Australia. Exposure to suspected child maltreatment was measured by linkage with state child protection agency data. The primary outcomes were the internalizing and externalizing scales of the Youth Self Report (YSR) at approximately 14 years of age.

RESULTS

The YSR was completed by 5,172 subjects (71.6%), with increased attrition of cases of notified maltreatment. After adjustment for potential confounders, notified maltreatment was significantly associated with both internalizing behavior and externalizing behavior at 14. When evaluated as non-exclusive categories of maltreatment, physical abuse, neglect, and emotional abuse were each significantly associated with both internalizing and externalizing behavior after adjustment. When evaluated using an expanded hierarchical scheme that included combinations of multi-type maltreatment, the following groups had significantly higher internalizing behavior after adjustment: emotional abuse (with or without neglect), and multi-type maltreatment including physical (but not sexual) abuse with neglect and/or emotional abuse. The following groups were associated with externalizing behavior after adjustment: emotional abuse (with or without neglect), and multi-type maltreatment including physical abuse (with neglect and/or emotional abuse), or sexual abuse (with neglect and/or emotional abuse, and/or physical abuse).

CONCLUSION

This study suggests that child neglect and emotional abuse have serious adverse effects on adolescent mental health and warrant the attention given to other forms of child maltreatment. Additionally, it confirms that young people who are notified for more than one type of maltreatment are at particular risk of adolescent mental health problems.

Does child abuse and neglect explain the overrepresentation of Aboriginal and Torres Strait Islander young people in youth detention? Findings from a birth cohort study

OBJECTIVE

Determine whether a history of family social disadvantage and/or child abuse and neglect explain the overrepresentation of Indigenous Australian young people in youth detention.

METHODS

Maternal survey data from the Mater University Study of Pregnancy was linked with child abuse and neglect and youth justice data from the Queensland Department of Families, Youth and Community Care.

RESULTS

Indigenous Australian children were 1.81 times more likely to be notified to child protection authorities for maltreatment and 1.77 times more likely to have that maltreatment substantiated. Indigenous Australian young people were 3.07 times more likely to have a youth justice history. When adjusted for social disadvantage, the odds of the Indigenous Australian youth having had involvement with the youth justice authorities remained 2.51 times that of their non-Indigenous peers. When adjusted for substantiated maltreatment, the odds of the Indigenous Australian youth having had involvement with the youth justice authorities remained 2.83 times that of their non-Indigenous peers. When adjusted for both social disadvantage and substantiated maltreatment, the odds of the Indigenous Australian youth having had involvement with the youth justice authorities remained 2.48 times that of their non-Indigenous peers.

CONCLUSIONS

The overrepresentation of Australian Aboriginal and Torres Strait Islander young people in the youth justice system, including Youth Detention, is only partly explained by their greater social disadvantage and by their greater experience of substantiated maltreatment, either separately or combined.

The anti-viral effect of sorafenib in hepatitis C-related hepatocellular carcinoma

BACKGROUND

Sorafenib is currently the only approved systemic therapy shown to have efficacy in the treatment of advanced hepatocellular carcinoma (HCC). Recent studies suggest that hepatitis C (HCV)-related HCC patients derive more clinical benefit from sorafenib than other subgroups, but the mechanism for this effect is unknown. In vitro data suggest that sorafenib may exert anti-viral properties, and thus our aim in this study was to evaluate potential anti-viral activity of sorafenib in patients with HCV-related HCC.

AIM

To evaluate potential anti-viral activity of sorafenib in patients with HCV-related HCC.

METHODS

We prospectively enrolled patients with HCV-related HCC treated with sorafenib for up to 6 months. Baseline clinical, viral and oncologic data were collected. Patients' HCV viral loads were obtained at various time points, and compared with their baseline viral levels. No patients received any known anti-viral therapy during this time.

RESULTS

Thirty-three patients were identified with baseline and subsequent HCV levels available for analysis. Six patients completed 6 months of full dose sorafenib, and comparisons of their HCV viral loads showed no significant change at week 24 (difference of means = 0.3500, CI: -0.1799-0.8799, P = 0.150), or the interim time points. Similarly, the HCV viral loads of all patients who received sorafenib and the viral loads of those patients who had tumour response to sorafenib showed no significant changes at any time point.

CONCLUSION

Despite preclinical data and previous subgroup analyses suggesting that sorafenib has an anti-viral effect against HCV, this study suggests that sorafenib lacks significant anti-viral activity in HCV patients with HCC.

Primary care physicians' knowledge of and experience with pharmacogenetic testing

It is anticipated that as the range of drugs for which pharmacogenetic testing becomes available expands, primary care physicians (PCPs) will become major users of these tests. To assess their training, familiarity, and attitudes toward pharmacogenetic testing in order to identify barriers to uptake that may be addressed at this early stage of test use, we conducted a national survey of a sample of PCPs. Respondents were mostly white (79%), based primarily in community-based primary care (81%) and almost evenly divided between family medicine and internal medicine. The majority of respondents had heard of PGx testing and anticipated that these tests are or would soon become a valuable tool to inform drug response. However, only a minority of respondents (13%) indicated they felt comfortable ordering PGx tests and almost a quarter reported not having any education about pharmacogenetics. Our results indicate that primary care practitioners envision a major role for themselves in the delivery of PGx testing but recognize their lack of adequate knowledge and experience about these tests. Development of effective tools for guiding PCPs in the use of PGx tests should be a high priority.